Bio-defense, communicable disease control, and surveillance of emerging infections are essential functions[unreadable] of public health. Infectious disease threats to public health encompass deliberate attacks, novel organisms,[unreadable] novel variants of old pathogens, antimicrobial-resistant strains, and new susceptible human populations.[unreadable] However, even familiar microorganisms are still major causes of morbidity and mortality. Strategies to better[unreadable] guide public health policy- and decision-making, particularly in situations of high uncertainty and high risk,[unreadable] are urgently needed.[unreadable] To address this problem, this project brings together four disciplines: public health, mathematical modeling of[unreadable] infectious diseases, computer simulation of complex systems, and cognitive psychology. The overall goal is[unreadable] create an integrated data and simulation environment for public health decision support adapted to the[unreadable] factors that drive public health decision-making. Three lines of research will proceed in parallel during the[unreadable] first half of the project. One line comprises the investigation of decision-making processes of public health[unreadable] epidemiologists and policy-makers using methods drawn from the discipline of cognitive psychology. Another[unreadable] line of research will entail the development of a detailed simulation of an urban population modeled after the[unreadable] Salt Lake Valley. A unique contribution of this specific part of the study is the evaluation of the impact of[unreadable] incorporating novel sources of data regarding demographics, activity levels, and health status into the[unreadable] establishment of the synthetic population. A third line of research will be to evaluate the conceptualization[unreadable] and interpretation of mathematical models of infectious disease by public health epidemiologists and policymakers.[unreadable] These research lines will then come together in four significant ways. First, the computer[unreadable] simulations will provide a more precise instrument to probe the factors that influence decision-making.[unreadable] Second, the information obtained from the analysis of decision-making processes will in turn inform the[unreadable] design of the prototype simulation test bed. Third, the simulations will facilitate investigation of transmission[unreadable] model acceptability for public health personnel. Fourth, a prototype simulation test bed will be deployed[unreadable] interactively in which the public health epidemiologist and policy-maker will be able to visualize multiple[unreadable] course of action and their effects, when confronted with a simulated outbreak.[unreadable]